On 10th May 1940 Hitler launched an attack into Belgium and France. What no one could have imagined on that day was that just six weeks later Marshall Pétain would sue for peace, signing an armistice which ceded three-fifths of French territory to the Germans. To add insult to injury, Hitler insisted that the armistice was signed in the same railway carriage in which Germany had been forced to admit defeat at the end of the First World War. So what had gone wrong for the Allies?

Signing the Armistice 1940

World War 1 had been a long-protracted conflict in which the opposing armies were static for the majority of the time, dug-in in extensive trench systems across northern Europe. Between the wars the Allies had assumed that if there were to be another war it would also be trench based and so they had planned accordingly. The French had used their huge defence budget to build a line of super-trenches with fortifications, tunnels, and underground bunkers on the German border (the Maginot Line), whilst the BEF supported French troops on the Belgian border. Therefore, when the British Expeditionary Force arrived in France at the outbreak of the Second World War they were ready for the prospect of a static defensive war. What the Allies were not prepared for, however, was Hitler’s intention to fight a swift, offensive war.

The Maginot Line

At dawn on 10th May 1940 29 German divisions began an invasion of the Netherlands and Belgium; in response the Allied commanders positioned the bulk of their forces defensively inside Belgium, playing into the hands of the enemy. What they were initially unaware of was that this attack was a feint and a further 45 divisions were thrusting forwards through the Ardennes. The French had believed this forested area to be impassable by enemy troops and so had left it woefully undefended. This second German force swiftly breached the Allied right flank, pushing them back towards the English Channel. With the fall of France and the disastrous retreat of the BEF from Dunkirk blame was placed on an innovative German tactic of blitzkrieg in which the enemy used the new technology of tanks and dive-bombers to force a swift victory. In German blitzkrieg means lightning war, a term which seemed apt for surprise attacks which made lightning fast advances into enemy territory, and in which air power supported ground troops to overwhelm the defenders. But blitzkrieg was not, in fact, a completely new idea.

Blitzkrieg – German attack through the Ardennes forest

The key elements of blitzkrieg are speed, surprise and superior firepower, and as such the concept can be traced back to Prussian military tactics in the early 19th century where limited resources meant that the only route to victory for the Prussians was through swift, powerful attack. Carl von Clausewitz, who made a detailed study of generals from Alexander the Great to Frederick II of Prussia, argued in his 1832 book ‘On War’ that all military force should be focussed in a single action against the enemy’s ‘centre of gravity’, its Schwerpunkt. Once this vulnerable point has been identified a frontal attack combined with a double flanking movement should crush the enemy, even if attacking troops had to be withdrawn from other areas and risks taken to achieve this objective.

Carl von Clausewitz

The German Alfred von Schlieffen developed a plan for a swift attack against his country’s old enemy, France, and this plan was put into action at the beginning of the First World War. Developing the ideas of von Clausewitz, Schlieffen’s aim was to achieve a swift victory by using 90% of the German army to move through Belgium and northern France to take Paris in a quick and decisive campaign. The plan was good in principle, but the attacking forces were slowed when they met with unexpected Belgian resistance, and this in turn gave the British time to prepare a defence at Mons. Although the Schlieffen Plan had failed it was believed to have a solid basis and so the idea of a lightning fast attack was used again in the spring offensive of 1918 when German armies reached within 75 miles of Paris before their advance was halted.

Heinz Guderian

Between the wars the theory of blitzkrieg was further developed by Heinz Guderian who advocated the integration of light tanks and dive-bombers to improve the manoeuvrability of the German army, insisting that every tank should have a radio to give them an added advantage. Hitler had fought in the trenches during World War 1 and wanted to avoid further trench warfare if at all possible, so when he saw Guderian’s plan he was very taken with the idea of victory through speed and movement. The German High Command were derisive of Guderian’s plan, telling Hitler that his claim that he could reach the French coast in a matter of weeks was idle boasting, but Guderian insisted that if they could break through the enemy frontline the panic and confusion caused amongst the civilian population would hamper any defending army’s movements to the front and so make success even more assured. Despite the misgivings of his senior officers Hitler was prepared to take the gamble. Germany tested its modern blitzkrieg tactic with a combination of both air and land action in the Spanish Civil war in 1938 and in Poland in 1939, with promising results.

When Germany pushed into the Ardennes in 1940 stukas were sent in just ahead of the armour to soften up the target and destroy rail links and communication centres. The German tanks, supported by infantry in half-track vehicles, began their advance at the same time with the bombing only stopping at the last minute, leaving the Allies no time to re-group. Once the first objective was taken the attacking army moved on leaving civilian refugees to clog the roads needed by the defending army, and also attacking the fleeing civilians to add to the fear and panic. The use of FM radio communication gave yet another advantage to the attacking army, enabling quick decisions to be made based on reliable evidence rather than waiting for orders from HQ. It was left to units following this initial attack to secure the gains made, thus freeing the panzer units to move on to the next Schwerpunkt.

French refugees, 1940

Blitzkrieg was so successful in the initial phase of the war that Germany went on to use the tactic on the Easter Front against the Russians during Operation Barbarossa, and in the North Africa campaign (Rommel, who commanded the German Afrika Korps, had been involved in the May 1940 attacks which forced the surrender of France). The Allies also adopted the ‘lightning war’ tactic in the Western Desert, on the Eastern Front, and after the D Day landings, relying on firepower to establish breakthroughs by fast-moving armoured units. Germany last used the blitzkrieg tactic during the Battle of the Bulge, yet the Allies continued to push forward and by the end of the war Hitler’s Third Reich was defeated by the very tactic which had brought it such success in 1940.

Fall of Berlin

Bibliography:

The Roots of Blitzkrieg by James Corum

Panzer, a Revolution in Warfare: 1939–1945 by Roger Edwards

The Blitzkrieg Legend: The 1940 Campaign in the West by Karl Heinz Frieser